Friction feed



' April 27,1943. c. a. PETERSON ET AL FRICTION FEED Filed Feb. 26, 1941 2 Sheets-Sheet 1 April 1943- c. G. 'PETER SON ETAL 2,317,481

' FRICTION FEED Filed Feb. 26, 1941 I 2 Sheets -Sheet 2 INVENTORS ATTORN EY Patented Apr. 27, 1943 FRICTION FEED Carl G. Peterson and Erick B. leterson, Providence, R. 1.

Application February 26, 1941, Serial No. 380,619

Claims.

Our present invention relates to feeding devices and more particularly to a friction grip feed for power presses and similar apparatuses.

The principal object of the present invention is to provide an intermittent feed for a power press or similar device which is adjustable to a fine degree of accuracy.

Another object of the present invention is to provide a feeding device for a power press or the like which is extremely accurate and uniform in operation to a high degree of precision.

Another object of the present invention is to provide a feed for power presses or the like which is reversible, so that the stock may be pulled or pushed through the power press.

Another object of the present invention is to provide a power press feed which can be kept well oiled to minimize surface wear without danger of slipping.

Another object of the present invention is to provide a power press feed which is frictionally operated, and which is easy and economical to manufacture and assemble.

With the above and other objects and advantageous features in view, our invention consists of a novel arrangement of parts more fully disclosed in the detailed description following and more specifically defined in the claims appended thereto.

In the drawings:

Fig. 1 is a perspective view of our invention attached to a. feed roll;

Fig. 2 is a vertical section taken along line 2-2 on Fig. 1;

Fig. 3 is a perspective view of tion grip members;

Fig. 4 is a perspective View of the brake arm;

Fig. 5 is a side elevation, partly in section, of the apparatus on the down stroke, or return movement;

Fig. 6 is a similar View on the up stroke or feeding movement;

Fig. 7 is a perspective View of the friction grip ring; and

Fig. 8 is a section taken on line 8-8 on Fig. 5.

Power presses and similar devices are provided with feeding mechanisms adapted to either push or pull the stock intermittently into operative position in .the press. The feed mechanism is usually adjusted so that it will feed just enough stock beneath the die to form the particular article with a minimum of waste. If the size or shape of the article is changed, the feed mechanism must accordingly be readjusted. The various types of feeding mechanism heretofore used one of the fricare difficult to adjust in that slippage, wear of the parts, and other factors prevent fine precision adjustments so that the stock can be fed uniformly through the press with a minimum of waste. The present invention is designed to provide a feeding mechanism which is simple in construction, which can be kept well oiled to prevent wear Without danger of slipping, which can be readily reversed for either a pulling or pushing feed, and which provides a fine adjustment for precision feeding.

Referring more in detail to the drawings illus trating our invention, we have shown our novel feed attached to a conventional power press roller feed device. This feed conventionally includes a stand Ii! in which a driven roller l l is rotatably mounted. An adjustable roller I 2 is mounted above the roller H and is geared to it, as at l3, the stock being either pulled or pushed into the press between the two rollers. The driven roller H is mounted on a shaft M which extends laterally from the stand li the feed mechanism of the present invention being mounted on the laterally extended portion of the shaft.

A friction grip member I 5, see Fig. 3, is mounted on the shaft i4 and comprises a hub portion H5 and a disc portion ll integral therewith. The disc portion l'l comprises a flat surface it), having a plurality of spaced threaded openings i9 extending therethrough, and a conical friction grip surface 29 tapering towards the outer edge of the disc portion. A second friction grip member 2 5, similar to the member I5, is also mounted on the shaft it (see Fig. 2) with its flat surface 22 contiguous to the surface is of the member l5. Spaced openings 23 are brought into alignment with the openings l9, and the members l5 and 2! are clamped firmly together as by machine screws 2%. The members it; and 2% are fixed to the end of the shaft M, as by a set screw 2 t in the hub of the member 2i The conical friction grip surfaces of the member l5 and 25 of the member 2| form a V-shaped channel in which the friction grip ring 26, shown in Fig. 7, is mounted. The ring 26 is made of stiff resilient material and is provided on each side with a friction grip surface 27 tapering inwardly at the same angle as the surfaces 2%] and 25 of the friction grip members l5 and 2|, so that the ring 26 nests in the V-shaped channel. The ring 26 is split, as at 23, and the free ends are provided with integral spaced parallel rectangular extensions 29 and 30, the extension 29 having a transverse opening 3| therethrough and the extension 30 having a transverse opening 32 extending therethrough. The edge of the ring 26 may also be provided with a plurality of notches 26a to permit oiling of the friction surfaces when the feed is in assembled position.

Referring to Figs. 1, 5, 6 and 8, we provide a block 33 having a slot or recess 34 into which the extensions 29 and 30 of the gripping ring are mounted. The block 33 is loosely pivoted to the lower ring extension 38 as by a pivot pin 35 extending through the opening 32. Mounted in the upper portion of the block 33 is a roller 36 extending transversely of the recess 34 and which is adapted to ride upon the upper surface of the ring extension 29. The block 33 is also provided with a rearwardly extending integral tab 31 which is pivotally attached to a link arm 38, the link arm 38 being reciprocated in the conventional manner by the power press mechanism (not shown).

As can readily be seen in Fig. 5, when the link 38 moves downwardly, the block 33 will be pivoted about the pin 35 sufiiciently to cause the roller 36 to clear the upper surface of the ring extension 23 so that the ring will slide freely in the V-shaped groove formed by the friction grip surface and without any gripping action. On the up stroke of the link arm 38, as shown in Fig. 6, the block 33 will be pivoted in the opposite direction and the pull of the link arm will cause the roller 36 to press downwardly on the extended portion 29 of the friction ring. It is obvious that this squeezing action of the ring extensions 29 and will contract the ring sufficiently to cause the ring friction surfaces 21 to frictionally engage and grip the surfaces 20 and 25 of the members l5 and 2 I. Upward movement of the link 38 will therefore cause rotation of the members H3 and 2|, shaft l4, and feed rollers H and I2. Thus, as the link arm 38 reciprocates, at each down stroke the friction grip ring will slide freely and the rollers will remain stationary, while at each up stroke the gripping action of the ring will cause rotation of the rollers and the feeding of the stock into the press.

In order to prevent excessive pressure of the roller 36 against the ring extension 29, which may result in the cracking of the friction ring, we provide a set screw adjustment 39 in the block 33, which acts as a stop and is so adjusted that the set screw will bear against the end of the extension 29 to limit the compressing action of the roller 36 on the up stroke; this also permits an adjustment for wear on the friction surfaces. The lower portion of the block 33 bears against the lower surface of the extension 30 on the down stroke. This provides a certain amount of play or lost motion between the down and up stroke. While the length of the stroke, which governs the amount of stock fed into the press, is adjustable on the link reciprocating mechanism, a final micrometer adjustment for hair line accuracy can be made by regulating the amount of lost motion or play of the pivoted block 33. This is accomplished by providing an adjustment screw 40 in the lower portion of the block 33, the end of the screw bearing against the lower surface of the extension 36 so that the adjustment of the screw 40 regulates the amount of play or lost motion in the block 33. The screw 40 may be locked in adjusted position as by a lock nut 4|.

While the friction ring will release sufficiently on the back stroke to permit return movement without operating the friction members or the feed rollers, there may be a slight amount of friction which might cause a reverse movement of the rollers. To prevent this, we provide a friction brake 42, see Figs. 1 and 4, which is mounted on the hub portion of the friction member 2|. The brake 42 comprises a split ring having an integral extending portion 43 which is rigidly bolted, by means of a bolt 44 extending through a slot 44a in the portion 43, to an L- shaped standard 45. The split portion of the brake 42 is provided with spaced parallel ears 43 having vertically aligned openings 41 connected by a bolt 48 with a heavy spring 49 between the bolt head and one of the ears 46. Pressure of the spring causes the brake 42 to exert a frictional clamping action on the hub portion of the member 2|. The tension of this spring is so adjusted that the frictional braking action between the brake 42 and the member 2| is not enough to interfere with the positive movement of the members during the feeding action or up stroke, but is greater than any friction which may develop between the ring 26 and the members l5 and 2| on the back stroke, thus effectively preventing any accidental rotation of the shaft l4 during the return movement of the friction ring.

Where a design or article is being stamped from sheet stock and there is metal left over, the stock is usually pulled through the press in the manner heretofore described and illustrated. However, where there is no residue, the sheet stock must be pushed into the press. The friction feed of the present invention may readily be applied to a pushing movement without altering the construction or operation. It is merely necessary to remove the block 33 from its pivotal connection 35 with the lower extension 38 of the friction ring, turn the block upside down, and pivotally attach the block 33 through the opening 3| to the upper extension member 29 of the friction ring. This reversal of the block 33 will cause the friction ring to grip on the down stroke of the link 38 instead of the up stroke and will cause it to release on the up stroke instead of on the down stroke, thus reversing the feed rollers of the power press.

In view of the minute adjustment permitted by the feed of the present invention, the stampings from the sheet stock may be placed quite close together, and the applicant has found that the positive gripping action of the present feed causes no variation in the movement of the stock. The feed of the present invention also readily renders itself to easy and rapid adjustment of the feed, thus permitting rapid changes in the type of articles being stamped. Furthermore, the applicant has found that the friction grip surfaces may be freely oiled to prevent surface wear without causing slipping and without detracting from the precision accuracy of the feed.

While we have described a specific embodiment of our invention, it is obvious that changes may readily be made in the size, shape and relative arrangement of the parts, without departing from the spirit and the scope of our invention as defined in the appended claims.

We claim:

1. In an intermittent feed, a rotatable shaft, a member locked to said shaft and having an annular friction grip surface, an annular split ring of resilient material engageable with said friction grip surface, the split ends having extensions extending therefrom in spaced adjacency, one extension having a hinge pin, a movable block swingingly mounted on said hinge pin and having a portion engageable with the other extension, whereby turning movement of said block towards said other extension initially engages said portion with said other extension to force said extensions towards each other for gripping engagement of said split ring with said friction grip surface, and then produces a forward movement thereof, and means on said block for limiting the engaging movement of said portion with said other extension.

2. In an intermittent feed, a rotatable shaft, a member locked to said shaft and having an annular friction grip surface, an annular split ring of resilient material engageable with said friction grip surface, the split ends having extensions extending therefrom in spaced adjacency, one extension having a hinge pin, a movable block swingingly mounted on said hinge pin and having a portion engageable with the other extension, whereby turning movement of said block towards said other extension initially enages said portion with said other extension to force said extensions towards each other for gripping engagement of said split with said friction grip surface, and then produces a forward movement thereof, and a second portion on said block engageable with said one extension, whereby return movement of said block away from said other extension produces an initial release of the gripping engagement and a delayed backward movement of the annular split ring.

3. In an intermittent feed, a rotatable shaft, a member locked to said shaft and having an annular friction grip surface, an annular split ring of resilient material en ageabie with said friction grip surface, the split ends having extensions extending therefrom in spaced adjacency, one extension having a hinge pin, a movable block swingingly mounted on said hinge pin and having a portion engageable with the other extension, whereby turning movement of said block towards said other extension initially engages said portion with said other extension to force said extensions towards each other for gripping engagement of said split ring with said friction grip surface, and then produces a forward movement thereof, a second portion on said block engageable with said one extension, and means for adjusting the engaging contact of said second portion, whereby return movement of said block away from said other extension produces an initial release of the gripping engagement and an adjusted delayed backward movement of the annular split ring.

i. In an intermittent feed, a rotatable shaft, a member locked to said shaft and having an annular friction grip surface, an annular split ring of resilient material engageable with said friction grip surface, the split ends having extensions extending therefrom in spaced adjacency, one extension having a hinge pin, a movable biock swingingly mounted on said hinge pin and having a portion engageable with the other extension, whereby turning movement of said block towards said other extension initially engages said portion with said other extension to force said extensions towards each other for gripping engagement of said split ring with said friction grip surface and then produces a forward movement thereof, means on said block for limiting the engaging movement of said portion with said other extension, and a second portion on said biock engageable with said one extension, whereby return movement of said block away from said other extension produces an initial release of the gripping engagement and a delayed backward movement of the annular split ring.

5. In an intermittent feed, a rotatable shaft, a member locked to said shaft and having an annular friction grip surface, an annular split ring of resilient material engageable with said friction grip surface, the split ends having extensions extending therefrom in spaced adjacency, one extension having a hinge pin, a movabl block swingingly mounted on said hinge pin and having a portion engageable with the other extension, whereby turning movement of said block towards said other extension initially engages said portion with said other extension to force said extensions towards each other for gripping engagement of said split ring with said friction grip surface, and then produces a forward movement thereof, means on said block for limiting the engaging movement of said portion with said other extension, a second portion on said block engageable with said one extension, and means for adjusting the engaging contact of said second portion, whereby return movement of said block away from said other extension produces an initial release of the gripping engagement and an adjusted delayed backward movement of the annular split ring.

CARL G. PETERSON. ERICK B. PETERSON. 

